The present invention relates to a spray-coating system.
Accordingly the invention relates to the spray-coating system containing a spraying implement, a support to which the spraying implement may be affixed in detachable manner by clamping means, first fluid-transmitting duct ends of fluid-transmitting ducts in the support configured opposite other, second fluid-transmitting duct ends of other fluid-transmitting ducts in the spraying implement and serving to convey fluids in-between when the spraying implement is affixed to the support, further containing seals at the fluid-transmitting duct ends to mutually seal the support and the spraying implement, said clamping means allowing to clamp the spraying implement against the support and the in-between seals being compressed.
The spray-coating system is especially well suited for spray-coating using liquid coating materials, through it also may be designed to spray-coat powders conveyed in a pressurized-gas flow, preferably a flow of compressed air.
A spray-coating system of this kind is known from the European patent document 0 846 498 A1. Therein, instead of a separately rotatable tightening element, it is the spraying implement itself which rotates in order to rotate a tightening element which is affixed to it relative to a support in order to clamp the latter two elements. In the course of this rotation, O rings between said implement and support being clamped in fluid-transmitting duct ends they contain. These seals only partly enter recesses in the spraying implement. The transverse motions taking place during clamping and releasing will abrasively shear said seals. Accordingly these seals must be exchanged on account of wear after the spraying implement has been mounted on and removed from the support several times. The support is in the form of an adapter""s plate which can be screwed tightly on a rest. This adapter makes it possible to affix the same or different spray-coating devices all designed with the same configuration of fluid-transmitting duct ends to a number of different rests such as robot arms or jacks exhibiting different configurations of fluid-transmitting ducts, and the same control programs may be used in all applications to drive the spray-coating system.
The objective of the invention is to reduce the seal wear between the spraying implement and the support in simple and economical manner and thereby to extend seal life and to preclude leakage flows when the coating material or other fluids, for instance compressed air or gas, solvents etc. are highly pressurized.
This goal is attained by clamping means that comprise a tightening element which is affixed to either of the group of spraying implement and support so as to be rotatable relative to it and comprises a first clamping surface, a second clamping surface being present at the other of said spraying implement or support, the axis of rotation of said tightening element being in the direction of tightening wherein the spraying implement and the support may be clamped against each other, and rotation of the tightening element relative said spraying implement and support allows rotating the first clamping surface while being clamped to the second clamping surface in order to clamp the spraying implement against the support and thereby to clamp the seals in-between.
Both in the present specification and the claims, the term xe2x80x9cfluidxe2x80x9d is considered in its basic form including especially xe2x80x9cliquidxe2x80x9d, in particular coating liquids or a solvent, gases, especially compressed air, and a flow of compressed air containing coating powder.